VIPER grinding on aerospace engine

Although the global aerospace and defence industry may take years to recover from the impact of the recession, Middle East carrier fleets are set to almost double their size by 2020, thanks to heavy investments in the sector and a growing wealthy population, according to consultants from AlixPartners.

Throughout the world, grinding machines have been developed for a variety of metalworking applications. High efficiency, heavy duty, high precision, mechanical and even a variety of intelligent CNC grinding technology has been widely used in the aerospace industry, and the processing of some of the key components is playing an increasingly significant role.

In the aerospace, budgets are not only bigger, but the conditions, rigors and requirements are greater. Things are generally done at a more leisurely pace and with significantly more advanced materials. What is becoming more relevant is high productivity rather than high speed, getting more parts out more quickly than just operating machinery at higher speeds and feeds.

VIPER grinding

VIPER grinding is an acronym for either Very Impressive Performance Extreme Removal or Vitreous Improved Performance Extreme Removal. This technology was developed at Rolls-Royce aircraft engine operations (www.rolls-royce.com) along with Tyrolit ( www.tyrolit.com), the Austrian grinding wheel manufacturer. In the process, extremely porous vitrified grinding wheels are used--so porous "they''re more air than wheel." The reason: the wheel is flooded with coolant, and it acts like a reservoir and consequently puts massive quantities of coolant right in the cut. For difficult - to - machine alloys, it can actually rough grind the material and have higher material rates than it could with milling or turning. Parts made with stainless or those with high nickel content are well suited to the process. It should be noted that they are not performing the grinding on a traditional grinding machine, but they are integrating the grinding into a conventional machine tool so that any additional turning, milling or drilling can be performed in the same setup.


"Aerospace engine manufacturing using viper grinding provides newfound efficiencies in applications involving difficult-to-machine materials and extraordinary finish."

As companies like Qatar Airways and Emirates continue to challenge the more established carriers for market share of long haul travel and cargo routes, high-productivity is indeed relevant. VIPER has helped Rolls- Royce slash lead-times for compressor blades, turbine blades and engine casings by factors previously unimaginable. Other benefits for the company include reduced thermal damage and consumable costs, as well as improved process consistency.

Aerospace engine manufacturing on a Makino i-Grinder G5 provides newfound efficiencies in applications involving difficult-to-machine materials and extraordinary finish. Purposely built from the ground up for VIPER grinding, G5 grinder is 10% quicker at machining nickel alloy components than the modified Makino A55 machining centre that it supersedes. Metal removal rate is of the order of 80cm3/min and the machine accepts parts nominally up to 300mm in diameter. The enhancement in grinding efficiency comes from a number of factors, including an increase in linear rapid traverse rate from 40 to 48m/min. Faster rotary workhead speed, which has more than doubled to 100 rev/min, is especially beneficial when grinding smaller components.

A big advantage of VIPER grinding on a horizontal machining centre is that in addition to abrasive wheels, other live and static tools, such as milling cuttNike Sportswear